Computer casing



FIG. 1 is a front view of a computer casing showing my new design;

FIG. 2 is a back view thereof;

FIG. 3 is a left end view thereof;

FIG. 4 is a right end view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a left back perspective view thereof. 

The ornamental design for a computer casing, as shown and described. 